Means for removing liquid mixtures from pressure vessels



Dec. 5, 1933 Tic. MARTIN ET AL MEANS FOR REMOVING LIQUID MIXTURES FROMPRESSURE VESSELS Filed March 25, 1932 INVENTOR S2 BY ATTOR N EYSPatented Dec. 5, 1933 UNITED STATES PATENT OFFICE MEANS FOR REMOVINGLIQUID MIXTURES FROM PRESSURE VESSELS New York 7 Application March 25,1932. Serial No. 601,283

20 Claims.

The invention is a device for the removal of a substantially uniformproportion of a mixture of fluids having widely different vaporpressures and liquid and gas phases from a container in which themixture is confined under pressure.

An example of such a mixture is one which contains carbon dioxide andethylene oxide in the approximate proportion of nine parts of the formerto one part of the latter. This material 10 is handled in conventionalhigh pressure tanks or cylinders such as those used for thetransportation of oxygen and, under normal conditions, the cylinders areapproximately half full of the liquid phase of the mixture which isunder about six hundred pounds pressure. Due to the widely differentvapor pressures or tensions of the two components the vapor phase islargely carbon dioxide while the liquid phase is a mixture of the twohaving a higher ethylene oxide content than the average of the entirecontent of the cylinder.

The mixture under discussion is used as a fumigant and under someconditions one cylinder may be used for several fumigations. To be mosteffective, the proportion of the mixture used for 5 each fumigationshould be substantially that of the entire content of the cylinder.Therefore, one of the objects of this invention is to provide a devicethat will remove this mixture from the cylinder in which it is containedin a substantially uniform proportion. Other aims, objects and novelfeatures will be apparent from the following description and theaccompanying illustration which is alongitudinal section through acylinder having a valve and an eduction tube attached thereto. P

The objects of this invention are attained by attaching an eduction tubeto the bottom of a valve employed to close a pressure vessel such as acylinder adapted to contain the above mentioned fumigating mixture andproviding this tube with suitable openings. These openings may be one ormore in number according to the accuracy of the proportion of themixture which is desired. In practice a suiliciently accurate proportionhas been attained by providing this tube with three openings. Thecombined area of these.

openings should be less than the area of the cylinder outlet through thevalve and best results have been obtained when the area of theseopenings is substantially 75% of that of the valve outlet, and the areaof the opening or bore in the eduction tube is greater than that of thecylinder or valve outlet. The purpose of keeping the area of the inletopenings to the eduction tube below that of the outlet of the eductiontube or valve is to secure an appreciable pressure drop between theinterior of cylinder and the interior of the eduction tube and therebyreduce to a negligible extent the undesirable eiiect of the staticcolumn of liquid in the eduction tube. I

With this device best results have been obtained when one inlet openingto the eductor tube is near the top of the tube in the gas phase of themixture; when another opening is near the center of the lower half nearthe middle, of the liquid phase of the mixture, and the third opening isas near the bottom of the eduction tube or cylinder as is practical.This arrangement of openings tends to compensate for the increasingconcentration of ethylene oxide in the liquid phase on account ofevaporation of a portion of the carbon dioxide to supply the increasingproportion of the cylinder volume devoted to the gas phase. 7

At the beginning of Y the process of drawing this mixture from acylinder the gas phase of the mixture is ejected through one opening inthe educator tube and the liquid phaseof the mixture is ejected throughtwo openings in this tube. Later when the surface of the liquid phasehas dropped below the central orifice, a change in the proportion of theliquid and gas phases occurs and gas is ejected through two openings andliquid through one. This condition continues until the surface of theliquid phase has dropped below the lower opening. From then on gas phaseonly is ejected. By this arrangement it has been found that theproportion of carbon dioxide and ethylene oxide in the mixture drawnfrom a cylinder remains substantially uniform until the cylinder ispractically exhausted and therefore regardless of whether the cylinderis entirely emptied or only a small portion iswithdrawn this proportionis maintained. In order to attain this result, however, the cylindervalve should always be fully open while the cylinder is being emptied.

The particular embodiment of the invention. shown in the drawingcomprises a cylinder valve 10 of the type usually employed in a cylinder19 adapted to contain oxygen. Extending down ward from the portion 11 ofthe valve 10, normally threaded into the top 20 of the cylinder, is ahollow copper eductor tube 12 extending substantially to the bottom 21of the cylinder and having the lower end thereof closed by means of aplug 13 brazed or soldered therein. The

eductor tube 12.. is provided with anopening or orifice 14 about 2inches below the bottom of the valve 10. A second opening 15 is provided.in the side of the eductor tube 12 from '5 to"8 inches above thebottom, and a third opening 16 is provided as near the bottom aspractical.

The openings 14, 15 and 16 are each .078 inch in diameter and thecombined areaof these three openings is substantially of the crosssectional area of either outlet opening 17 or 18 of the valve 10, whichis less than the cross sectional area of the interior of the eductiontube.

The tube 12 is secured to the lower end of the valve 10 by means ofbrazing or soldering but other means may be used 3 as long as a tightjoint is secured between the tube and the valve. Also one or moreopenings may be employed in the eductor tube and the distance betweenthe openings and their position with respect to the cylinder may bevaried without departing from the spirit of the invention or the scopeof the claims.

We claim:

1. Means for the eduction of a uniform proportion of a mixture of fluidshaving liquid and gas phases and widely different vapor pressures from acylinder in which the mixture is confined under pressure, comprising; aneduction tube attached to the outlet of said cylinder and extendingsubstantially to the bottom thereof; said eduction tube having threeopenings in the wall thereof; one of said openings being near the top ofsaid tube in the gas phase of said mixture; one of said openings beingsubstantially at the center of the lower half of said tube in the liquidphase of'said mixture and the other of said openings being substantiallyat the bottom of said cylinder; the area of the inside of said eductiontube being greater than that of the outlet of said cylinder, and thecombined area of the three openings in said eduction tube beingsubstantially 75% of the area of the outlet .of said cylinder.

2. Means for the eduction of a uniform proportion of a mixture of fluidshaving liquid and gas phases and widely different vapor pressures from acylinder in which the mixture is confined under pressure, comprising; aneduction tube attached to the outlet of said cylinder and having aninterior area greater than said outlet; and a plurality of openings inthe wall of said eduction tube; one of said openings being near the topof said tube in; the gas phase. of said mixture.

3. Means for-the eduction 'of a uniform-proportion of a mixture offluids having liquid and gas phases and widely different vapor pressuresfrom a cylinder in which the mixture is confined under pressure,comprising; an eduction tube attached to the outlet of said cylinderandextending substantially to the bottom thereof; a plu- 'rality ofopenings in the .wall of said eduction tube; the number of said openingsin the liquid phase of said mixture being twice the number in the gasphase of said mixture when said cylinder is fully charged.

4. Means for the eductionof a uniformproportion of a mixture of fluidshaving liquid and gas phases and widely different vapor pressures from acylinder in which the mixture is confined under pressure, comprising; aneduction tube attached to the outlet of said cylinder andextendingsubstantially to the bottom thereof; a plurality of openings inthe wall of said eduction tube; the number ofsaid openings in the liquidphase of said mixture being greater than the number in the gas phase ofsaid mixture when said cylinder is fully charged.

5. Means for the eduction of au'nifoim proportion of a mixture of fluidshaving liquid nd Gas phases and widely different vapor pressures from acylinder in which the mixture is confined under pressure, comprising; aneduction tube attached to the outlet of said cylinder and extendingsubstantially to the bottom thereof; a plurality of spaced openings inthe wall of said eduction tube; the area of said openings being lessthan the area of the outlet of said cylinder.

6. Means for the eduction of a uniform proportion of a mixture of fluidshaving liquid and gas phases and widely different vapor pressures from acylinder in which the mixture is confined under pressure, comprising; aneduction tube extend- .ing from the outlet of said cylindersubstantially widely different vapor pressures and gas and liquidphases; a valve attached to the top of said cylinder and having anoutlet opening therethrough; an eduction tube attached to said valve andextending substantially to the bottom of said cylinder; an opening inthe wall of said eduction tube near the top to the gas phase of saidmixture; an opening in the wall of said eduction tube substantially inthe center of the lower half to the liquid phase of said mixture whensaid cylinder is fully charged; and an opening in the wall of saideduction tube at substantially the bottom thereof; the interior area ofsaid eduction tube being greater than the outlet area of said valve; anda combined area of the openings in the wall of said eduction tube beingsubstantially 75% that of the outlet opening in said valve.

8. In combination, a cylinder adapted to con tain" mixture of fluidshaving widely different vapo --,pressures and gas and liquid phases; avalve having an outlet therethrough for said cylinder; an eduction tubeattached to said valve in said cylinder and extending substantially tothe bottom thereof; a plurality of openings in the wall of said eductiontube; the number of said openings in the liquid phase of said mixturebeing twice that in thegas phase of said mixture when said cylinder isfully charged.

9. In combination, a cylinder adapted to contain a mixture of fluidshaving widely different vapor pressures and gas and liquid phases; avalve having an outlet therethrough for said cylinder;

an eduction tube attached to said valve in said j cylinder and extendingsubstantially to'the bottom thereof; a plurality of openings in the wallof said eduction tube; the number of said openings'in the liquid phaseof said mixture being greaterthan the number in the gas phase of saidmixture when said cylinder is fully charged.

10. In combination, a cylinder adapted to contain a mixture of fluidshaving widely different vapor pressures and gas and liquid phases; avalve having an outlet therethrough for said cylinder; an eduction tubeattached to said valve in'said cylinder and extending substantially tothe bottom thereof; a plurality of openings in the wall of said eductiontube; the interior area of said eduction tube being greater than thearea of the outlet opening in said valve; and the combined area of theopenings in the wall of said eduction tube being less than the area ofthe outlet opening in said valve.

11. The combination with a container for a mixture of fluids havingwidely different vapor pressures and gas and liquid phases underpressure, of means whereby a mixture of substantially uniformproportions may be delivered from said container from the time it issubstantially full until it is substantially empty.

12. In a cylinder adapted to contain a mixture of fluids having gas andliquid phases and widely different vapor tensions under pressure; meansfor removing said mixture in substantially uniform propostion comprisinga valve in said cylinder having an outlet therefor; a tube having aninterior area greater than said outlet extending therefrom substantiallyto the bottom of said cylinder, and a pluraliy of openings in the wallof said tube having a combined area less than the area of said outlet.

13. In a cylinder adapted to contain a mixture of fluids having gas andliquid phases and widely different vapor tensions under pressure; meansfor removing said mixture in substantially uniform proportion comprisinga valve in the top of said cylinder having an outlet therefor; aneduction tube extending from said outlet substantially to the bottom ofsaid cylinder, and three openings of uniform size in the wall of saidtube, one near the top, one near the bottom, and one near the center ofthe lower half.

14. In a cylinder adapted to contain a mixture of fluids having gas andliquid phases and widely different vapor tensions under pressure; acombination of means for removing said mixture comprising a closableoutlet and an eduction tube having a bore and a plurality of inletopenings; means for maintaining a substantially uniform proportion inthe mixture removed comprising the position of said openings withrespect to said cylinder, and the relative area of said outlet, saidbore, and said openings; and means for reducing the effect of the staticcolumn of liquid in said tube comprising the relative area of saidoutlet and said inlet.

15. In a cylinder adapted to contain a mixture of fluids having gas andliquid phases of substantially equal volume and widely different vaportensions under "pressure; means for removing said mixture insubstantially uniform proportion comprising a closable outlet for saidcylinder; an eduction tube connected with said outlet and extendingsubstantially through both phases of said mixture; said eduction tubehaving an inlet opening in the gas phase of said mixture, an openingnear the bottom of the liquid phase of said mixture, and an opening thatis changed from the liquid phase to the gas phase of said mixture whensubstantially half of the liquid phase has been removed.

16. In a cylinder adapted to contain a mixture of fluids having gas andliquid phases under pressure; means for removing said mixture insubstantially uniform proportion, comprising a closable outlet for saidcylinder and an eduction tube having a bore larger than said outletconnected with the interior end thereof and extending downward into saidmixture; the wall of said tube having a plurality of spaced inletopenings having a combined area substantially of the area of saidoutlet.

17. In a cylinder adapted to contain a mixture of fluids having gas andliquid phases and different vapor tensions under pressure; thecombination of means for removing said fluids in substantially uniformproportion comprising a closable outlet for said cylinder above saidmixture; an-eduction tube extending downward in said cylinder from saidoutlet substantially to the bottom. of said cylinder; and a plurality ofvertically spaced openings in the wall of said tube; and means forproducing a reduction in pressure between the interior of said cylinderand the interior of said tube during removal of said mixture'to reducethe effect of the static column of liquid in said tube.

18. In a cylinder adapted to contain a mixture of fluids having gas andliquid phases of substantially equal volume and widely different vaportensions under pressure; a combination of means for removing saidmixture comprising a closable outlet and an eduction tube; means forreducing the eifect of the static column of liquid in said tube duringremoval of said mixture comprising means for maintaining a pressure insaid tube substantially lower than that in said cylinder; and means formaintaining a substantially uniform proportion in the mixture removedcomprising means for increasing the proportion of the gas phase of saidmixture during removal.

19. In a cylinder adapted to contain a mixture of fluids having gas andliquid phases under pressure; the combination of means comprising aneduction tube for removing said mixture; means for maintaining asubstantially uniform proportion in the mixture removed comprising,means for maintaining a pressure in said tube substantially below thatin said cylinder, and means for increasing the proportion of the gasphase of said mixture during removal.

20. In a cylinder adapted to contain a mixture of fluids having liquidand gas phases and widely different vapor tensions under pressure;

means for removing said mixture in substantialliquid phase whenapproximately half or more of said liquid phase has been removed.

THOMAS C. MARTIN. SIMON MEYER.

